The present invention relates to a composite textured yarn comprising cellulose filaments and synthetic fiber filaments of a polyester etc. The present invention relates, in more detail, to a composite crimped yarn which gives a weft knitted fabric having no weft bar, a high-quality appearance, and glossiness and a feeling of cellulose filaments and excellent in shrinkage proofing properties and setting properties, and a weft knitted fabric in which the composite crimped yarn is used.
Since cellulose filaments are excellent in glossiness, feeling, moisture absorption and drapability, and have a good touch, they show excellent properties as materials for apparel such as innerwear and outerwear. However, the cellulose filaments have drawbacks related to the physical properties and their use as explained below. A knitted fabric prepared therefrom tends to form weft bar, and does not have a high-quality appearance. It has poor dimensional stability and strength when it is wetted, and it tends to form creases. In order to remove such drawbacks, a composite textured yarn in which synthetic fiber filaments of polyester etc. are used in combination has heretofore been proposed.
For example, Japanese Unexamined Patent Publication (Kokai) No. 62-299527 proposes a composite combined yarn which is obtained by uniformly combining, by fluid interlacing, a polyester fiber spun at a winding speed of at least 7,000 m/min and having a low boil-off shrinkage and a regenerated cellulose fiber, which suppresses hardening of the feeling caused by shrinkage of the polyester filaments subsequent to dyeing, and which has the hand touchness of cellulose. However, the yarn tends to form weft bar because the polyester is not subjected to fine crimping in contrast to that in the present invention. Moreover, the yarn tends to have a moire tone during dyeing because it shows poor uniform combining properties when compared with a yarn which is false-twisted. That is, the yarn is poor in a dyeing quality.
Furthermore, Japanese Unexamined Patent Publication (Kokai) No. 8-170238 proposes a composite false-twisted yarn prepared by doubling, or combining and false-twisting regenerated cellulose filaments and a self-crimping type of polyester filaments, namely, polyester filaments composed of a composite fiber that is formed by bonding two components differing from each other in shrinkage. However, the yarn is heated only when false twisted, and it is not heated in a setting zone after untwisting, whereby the degree of crimping is increased. As a result, a circular knitted fabric prepared therefrom has the following disadvantages. The polyester fiber tends to be projected out the surface, and the fabric hardly has the glossiness and hand touchness of cellulose filaments, and has a low quality because it has a waxy hand touchness specific to polyester and a bulky and elastic hand touchness specific to a synthetic fiber.
Japanese Unexamined Patent Publication (Kokai) No. 6-330424 proposes a process for producing a fabric excellent in hand touchness, which comprises fluid interlacing a cellulose-based fiber as a sheath yarn and a composite fiber as a core yarn that is formed from (a) a polyester obtained by copolymerizing in a specific proportion a component having a side chain type of specific polyalkylene groups, isophthalic acid, a polyalkylene glycol component, etc., and (b) at least another fiber-forming polymer, and alkali treating the resultant combined yarn or a fabric formed from the combined yarn, thereby dissolving and removing at least part of the copolymerized polyester. However, in the process, cellulose filaments are overfed so that the proportion of the cellulose fiber increases in the sheath yarn of the combined yarn, and loop-like or curl-like protrusions of the cellulose filaments are formed by a fluid pressure of 4 to 10 kg/cm2. Consequently, a knitted fabric prepared from the combined yarn has the following disadvantages: the fabric has little of the glossiness of cellulose filaments and has a low quality appearance; and moreover, weft bar are likely to be formed because the polyester fiber in the core portion is not crimped.
Japanese Unexamined Patent Publication (Kokai) No. 9-3740 discloses a composite textured yarn obtained by combining and false-twisting synthetic fiber filaments that show a boil-off shrinkage of 8 to 60% and cellulose filaments. However, since the yarn is not heat set at temperatures of 100 to 250xc2x0 C. after untwisting following the false-twisting step, the synthetic fiber filaments manifest crimping when treated with hot water during dyeing or the like, and the cellulose filaments are considerably opened because the hot water shrinkage of the synthetic fiber is large. As a result, the cellulose filaments project out the surface of the composite textured yarn, and the loops of the yarn become disordered when the yarn is formed into a knitted fabric, thereby showing a low quality appearance and giving a poor hand touchness.
Japanese Unexamined Patent Publication (Kokai) No. 5-163645 discloses a technology of suppressing the formation of weft bar by the use of a composite yarn obtained by doubling and twisting a false-twisted yarn of viscose rayon and a polyester yarn. However, since the composite yarn is twisted, it cannot have the glossiness and hand touchness of cellulose filaments. The composite yarn has a waxy hand touchness specific to a polyester fiber because a polyester fiber is doubled and twisted. Moreover, although formation of weft bar is suppressed, the suppression is insufficient because the polyester yarn is not crimped.
As explained above, even when a decrease in the dynamic strength and the shrinkage, of a cellulose fiber in a wet state, of yarns obtained by conventional technologies can be suppressed, the yarns have a waxy feeling of a polyester fiber, and a bulky and elastic feeling specific to a synthetic fiber. None of the yarns have given a weft knitted fabric of high quality having no weft bar and glossiness and a hand touchness very close to that of a yarn containing 100% of cellulose filaments.
An object of the present invention is to provide a composite crimped yarn which gives a weft knitted fabric having no weft bar, an appearance of high quality, and glossiness and a hand touchness of cellulose filaments, and being excellent in shrinkage proofing properties and setting properties, and a weft knitted fabric in which the yarn is used.
As a result of intensively carrying out investigations in view of the drawbacks as explained above, the present inventors have achieved the present invention.
That is, the present invention provides a composite crimped yarn which comprises from 50 to 90% by weight of cellulose filaments and synthetic fiber filaments, which shows a crimping elongation of 0.1 to 4.0%, and which is combined and false-twisted, and a weft knitted fabric which is formed from the composite crimped yarn, and the cellulose filaments of which show a surface occupation rate of at least 70% on the knitted fabric and more than weight proportion.